Bump postcss-loader from 5.1.0 to 5.2.0

Bumps [postcss-loader](https://github.com/webpack-contrib/postcss-loader) from 5.1.0 to 5.2.0.
- [Release notes](https://github.com/webpack-contrib/postcss-loader/releases)
- [Changelog](https://github.com/webpack-contrib/postcss-loader/blob/master/CHANGELOG.md)
- [Commits](webpack-contrib/postcss-loader@v5.1.0...v5.2.0)

Signed-off-by: dependabot[bot] <support@github.com>

package.json

@@ -71,7 +71,7 @@
         "nookies": "^2.5.2",
         "path-to-regexp": "^6.2.0",
         "postcss-flexbugs-fixes": "^5.0.2",
-        "postcss-loader": "^5.1.0",
+        "postcss-loader": "^5.2.0",
         "postcss-normalize": "^9.0.0",
         "postcss-preset-env": "^6.7.0",
         "prettier": "^2.2.1",